Neural network based feedback linearization control of a servo-hydraulic vehicle suspension system

This paper presents the design of a neural network based feedback linearization (NNFBL) controller for a two degree-offreedom (DOF), quarter-car, servo-hydraulic vehicle suspension system. The main objective of the direct adaptive NNFBL controller is to improve the system's ride comfort and handling quality. A feedforward, multi-layer perceptron (MLP) neural network (NN) model that is well suited for control by discrete input-output linearization (NNIOL) is developed using input-output data sets obtained from mathematical model simulation. The NN model is trained using the Levenberg-Marquardt optimization algorithm. The proposed controller is compared with a constant-gain PID controller (based on the Ziegler-Nichols tuning method) during suspension travel setpoint tracking in the presence of deterministic road disturbance. Simulation results demonstrate the superior performance of the proposed direct adaptive NNFBL controller over the generic PID controller in rejecting the deterministic road disturbance. This superior performance is achieved at a much lower control cost within the stipulated constraints.

Ehtiwesh, I.A.S. and Dorovic, Z. (2009). Comparative analysis of different control strategies for electro-hydraulic servo systems, Proceedings of the World Academy of Science, Engineering and Technology 56(6): 906-909.

Eski, I. and Yildrim, S. (2009). Vibration control of vehicle active suspension system using a new robust neural network control system, Simulation Modelling Practice and Theory 17(5): 778-793.

Fallah, M.S., Bhat, R. and Xie, W. (2009). $H_∞$ robust control of active suspensions: A practical point of view, Proceedings of the 2009 American Control Conference, St Louis, MO, USA, pp. 1385-1390.

Gao, B., Tilley, D.G., Williams, R.A., Bean, A. and Donahue, J. (2006). Control of hydropneumatic active suspension based on a non-linear quarter-car model, Proceedings of the Institute of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 220(1): 75-31.

Pedro, J.O. and Mgwenya, T.R. (2004). LQR control of a full car active suspension with actuator dynamics, Proceedings of the 4th South African Conference on Applied Mechanics, SACAM'04, Johannesburg, South Africa, pp. 1-9.